Old CDs Spin a New Tune as Sewage Water Treatment

There’s a new use for the CDs you abandoned for MP3 files. At this month’s Frontiers in Optics meeting in Florida, Taiwanese researchers will present an intriguing new way of breaking down sewage – spinning CDs.

The researchers used the large surface area of optical discs to grow small zinc oxide nanorods, which they explain are about a thousandth of the width of a human hair. The zinc oxide is much like a photocatalyst and, once illuminated with light, will break apart organic molecules in the sewage.

While the disc spins, contaminated water can spread out over the surface as a thin film that allows light to pass through easier thus speeding up the degradation process.

The new method, according to Din Ping Tsai, a physicist at National Taiwan University, is an inexpensive one, which can re-use old discs and cut down on waste.

The researchers will be presenting their research and experiments to colleagues and contemporaries. They will explain how the discovery can be expanded on and if the process can be applied on a larger scale.

The video below shows the photocatalytic reactor in action:

Jonathan Keane

Jonathan Keane is a engineering enthusiast. You can also find Jonathan on Google+.